‘Bells and whistles’ not always best for machining

NEW technology is generally assumed to bring improvements to equipment, but sometimes a step forward in one area may bring two steps back in another.

600 Machine Tools ’ general manager, Cliff Purser, says some OEM’s have focused on equipping machining centres with “bells and whistles” at the expense of more basic requirements.

Purser told Manufacturers’ Monthly manufacturers often choose equipment with latest features and neglect core requirements such as rigidity and accuracy which he says are “the fundamentals of any machine tool”.

Equipment bases should be made from solid materials such as polymer concrete. “That isolates vibration and heat generation which gives the machine dual stability; less thermal deviation and better repeatability.”

According to Purser, manufacturers should carefully evaluate complex equipment such as multi-tasking machines. “People look at multi-tasking machines and think they’re going to be the ‘be-all-and-end-all’ of the job, but that’s not always the way,” he said.

Although multi-tasking machines can in some cases complete a job from raw input to finished part, adding features to the machine may bring disadvantages.

“Let’s say you get a standard CNC machine and it’s got a maximum turning diameter of 250mm. By putting some other features on, it might reduce that turning capacity because there’s not enough room in the machine itself,” Purser said.

Realtek Technologies’ MD, Brian Power, agrees that not every development improves equipment performance.

Power says he is seeing electronics and electrical systems increasingly replacing hydraulic and pneumatic controls in machines. He told Manufacturers’ Monthly this is generally making equipment cheaper and more reliable, but electrical systems may slow operation in some parts of the machine.

“In the case of main slideways and main ball screws, [electrical control] is very fast, but we’ve noticed where they’ve switched from a hydraulics slide for a parts catcher to a fully electrical one, it’s actually made it slower,” he said.

As with any business decision, the relative pros and cons of the equipment must be considered, and these may not directly relate to throughput. For example, removing hydraulics and pneumatics can reduce air compressor energy consumption and can reduce the cost of consumables such as hydraulic oil.

Developments in technology are also leading manufacturers to favour different types of equipment than they did in the past.

“Ten years ago, the market tended to buy two-axis and three-axis machines and maybe they’d have a milling function. These days, the dominance in the market is...from the multi-axis, between six and 12-axis simultaneous machines.”

Power puts this primarily down to rapid processing speeds the machines can achieve. “If 12 things have to happen to a part and those 12 things can happen at the same time, you can carve the cycle time down,” he said.

Sliding head machines, or Swiss type machines are also becoming more popular due to their precision. “Applications are everything from watch pins to parts for the car,” Power said.

This style of machine was originally developed in Switzerland for watch manufacture but Power says the concept of the headstock moving has broadened to enable long products to be turned accurately.

“For Australia, and for most western countries...they’ll get their edge from being able to cut faster and produce better quality parts quicker,” Power said.

Changing demographics

Power’s advice is to “buy reliability, buy best technology and up-skill your people”.

With increasing competition from low cost countries such as Taiwan and Korea, the main competitive advantages Australian manufacturers have are the quality and skill levels of staff, our ability to innovate and apply advanced technology.

Machining centre sales indicate a proportion of Australia’s industry is already positioning itself to take advantage of high technology.

According to Power, most of the better quality imported machining centres are produced in Germany and Japan. Last year, Australian manufacturers purchased 13 machining centres from Germany and 54 from Japanese suppliers.

The middle market for machining centres is largely made up of the US-built machines and Korean machines. There were 42 machines purchased from the US and 26 from Korea in 2004.

Machines sold in this segment of the market are less expensive than those in the high end, but also tend to be slower and less sophisticated. “They’re just reliable and get the job done and there seems to be some demand for that in the general jobbing and start up companies,” Power said.

A fair number of producers are still purchasing low end equipment, however, with 54 Taiwanese machines imported in 2004. Power says Taiwanese and Chinese equipment tends to be of lower quality, and tends to wear out more quickly than equipment purchased from elsewhere. This kind of equipment may be suitable for simple tasks, but is generally a less cost effective option for manufacturers aiming to be competitive in the longer term.

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